Reciprocating engine



Feb. 4, 1930. HAMMOND 1,745,793

RECIPROCATING ENGINE Filed Feb. 25, 192'? 5 Sheets-Sheet l INVENTOR.

BY WJZ A TTORNEY Feb. 4, 1930. O, HAMMOND 1,745,793

REC IPROCATING ENGINE Filed Feb. 25, 1927 3 Sheets-Sheet 2 IN V EN TOR.

A TTORNEY Feb. 4, 1930. 0, HAMMOND 1,745,793

REC-IPROCATING ENGINE F'iled Feb; 25, 1927 s Sheets-Sheet 5 INVENTOR.

' ATTORNEY Patented Feb; I 1930 OLI; HAMMOND, OI JACKSON, CALIFORNIA nncrrnocnrme ENGINE Application filed February 25, 1927. serial No. 170,891.

My invention relates to a reciprocating engine and particularly to a means for transmitting power between the piston and power shaft of; the engine.

An important object of the invention is.

the-incorporation with a reciprocating engine of a power-transmitting means 1 n the nature of a toggle-thrust, whereby maxlmum 7 power is delivered with minimum resultant '10 vibration.-

Another object of the invention is to provide means of the class described whereby a particularly smooth and eflicient power flow will be provided.

Another object of the invention is to provide means of the character described which lessens and so distributes the lateral crank shaft thrust that engine vibration is practically eliminated. I

A further object of the invention is to provide means of the character described in which the side thrust of the (piston against the cylinder walls is minimize thereby conserving power and preventing the mutual wear of these parts.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be set forth in' the following description of. the preferred form of the invention which is illustrated. in the drawings accompanying and forming part of the specification. It is to be understood, however, that I do not limit myself to the showing made by the said drawings and description, as I may adopt variations of the preferred form within the scope of my invention.

Referring to said drawings: a Figure 1 is an'end view, partly in section, 9 of an internal combustion engine embodying I my invention, with the piston and the various other movingparts thereof positioned as at the beginning of a power stroke. Figures 2, 3, and 4 are diagrammatic views disclosing the relations of the connections between the piston and the power'shaft for different stroke'positions of the crank-shafts, the latter advancing in steps of 90 degrees. Figures 5 and fifareenlarged' fragmentary views of part of the structure, portions thereof being shown in section.

As herewith particularly illustrated, the power transmitting means of my invention is associated with an internal combustion engine 7, said engine having one or more cylinders 8 provided in a cylinder block 9 of a usual structure and having provided therebelow a crankcase 11. Mounted in the cylinder for reciprocation therein is a piston 12 provided with a wrist pin 13 for pivotally securing a piston rod thereto. Disposed in the crankcase to extend longitudinally of the engine are like crankshafts 14 and 15 and a power shaft 16, such shafts being parallelly 6! related and carried in suitable bearings .(not shown). The power shaft 16, it will be noted, is spaced equally from the crank-shafts 14 and 15, and. is operatively connected thereto by means'of a gear 17 mounted thereon and meshing with a pair of gears 18 and 19 mounted on the respective crank-shafts, the

gears 18 and 19 being of like size whereby the rotative speeds of the shafts 14 and 15 will be equal.

- Pivotally secured to the wrist pin 13 is a piston rod 20, while pivotally secured to the crank-pins 21 and 22 of the crank-shafts 14 and 15 respectively are connecting rods 23 and 2 1. The different rods, it will now be noted, are pivotally interconnected at their free ends for relative rotation about a pivot pin 25, whereby the rods 23 and 24 serve to provide a toggle joint between the crankpins 21 and 22, with the piston rod 20 acting as a thrust member for the joint.

To provide the desired pivotal connection of the rods, the piston rod 20 is hereshown provided at its free end with a yoke 26, between the arms 27 of which the pin-receiving 9o portions 28 of the rods 23: and 24 respectively are arranged to engage in halved relation to form in effect a rule joint, whereby the longitudinal axes ofthe various rods will be disposed and constrained to move in a common 95 plane. The pin 25 is preferably removable, and as here shown is provided at its extremities with reduced and threaded portions 29 on which nuts 31 are arranged to be disposed whereby the pin maybe secured in position on 10c the yoke. Preferably, and as here shown, the connecting rods 23 and 24 are of adjustable length, such adjustability being'hereshown provided by having the rod portions 28' arranged for threaded engagement with the intermediate rod portions 32. The crank-pin engaging portions of the rod, it will be noted, comprise cooperating half-bearin gs 33 and 34, the former being formed integral with the rod portions and the latter being secured to the former by means of bolts 36, the-crank-pin bearing structure thus provided being a usual one. 1

Referring now particularly to the relative position of the moving parts as disclosed in the Figures 1 to 4 inclusive, it will be noted that in Figure 1 the piston isshown disposed at its innermost position, as at the beginning of the power and suction strokes of a fourstroke cycle engine, and that at such time the crank-pins of the crank-shafts 14 and 15 are both ahead of their dead-center positions with respect to the connecting rods. In Figures 2, 3 and 4, it will be noted that the crank-pins are shown as respectively advanced 90, 180 and 270 degrees from their positions in Figure 1.

A consideration of the relations of the rods to the cranks at and between the crank positions shown, discloses that the greater portion of the working and suction strokes takes place during the first quarter-turn represented, that the toggle effect is greatest during the second quarter-turn, that the connecting rods are never on dead-center when the piston is in a limiting position, and that the connecting rods are never simultaneously on dead-center. In view of the foregoing, it will now be clear that a smooth power flow between the piston and power shaft is provided and that, through the force-balancing effect of the geared connection between the drive-shaft and the crank-shafts, vibration and transverse thrusts on the crank-shafts are reduced to .a minimum never obtained in the usual connecting-rod installation. 4

It will be noted that the shafts 14 and15 and 16 may be variously relatedto each other and to the cylinder, andthat the different rods must be proportioned in accordance with such positions of the shafts. As here shown, however, the shaft 16 is disposed in the axial line of the cylinder, the rods 23 and 24 are of equal length, and the crank-pins are equally offset from their respective shafts, thus minimizing the number of parts to be designed. Under these conditions, the plane of the crank-shafts is preferably inclined to the horizontal, the lower crank-shaft being that at the'side of the cylinder toward which the piston rod is disposed during the working .stroke, as is here shown. In this manner, the

lead angle of the cranks at the beginning of the power stroke is increased whereby the effective working torque is correspondingly greater and the lateral thrust on shafts is minimized.

the crank- It is noted that during the operation of the device, the joint at the pin 25 moves in a predetermined path ABC'D,' such joint constitutin in effect a floating cross-head.

And it wil be further noted that the device of my invention may be applied to the conversion of rectilinear motion into a rotative motion, orvice-versa, in other mechanisms than reciprocating engines without departing from the spirit of my invention. 1

From the foregoing description taken in illustrative and thatsuch changes may-be made, when desired, as fall within the scope of the appended claims.

Having ,thus described my invention, I claim as new and desire to secure by Letters Patent of the United States, the following:

1. In combination with a reciprocating member providing a wrist pin and a rotatable shaft disposed in the plane of alignment with the bath of movement of said member, crank shafts at opposite sides of said path of movment operatively connected to said first shaft and providing crank pins, and links pivotallyconnected at a common point and each extending therefrom to a pivotal connection with a different one of said Wrist and crank pins.

2. In combination with a reciprocating piston providing a wrist pin, and a rotatable shaft disposed in the plane of alignment with the path of movement of said member, parallel crank shafts equally spaced at opposite sides of said path of movement operatively connected to said first shaft and providing crank pins, and links pivotally connected at a common point spaced from the axis of said wrist pin for relative movement in a common plane and each extending from said point to a pivotal connection with a different one of said pins. V r

3. In combination with a reciprocating member providing a wrist pin and a rotatable shaft disposed transversely of the path of movement of said member, parallel crank shafts operatively connected to said first shaft and defining a plane extending. substantially perpendicularly to said path and providing crank pins, and links pivotally connected at a common point and each extending from said point to a pivotal connection with a different one of said wrist and crank pins.

4. In combinationwith a reciprocating member providing a wrist pin and a rotatable shaft disposed in the plane of alignment with the path of movement of said member, a pair of mutually coplanar crank shafts disposed transversely and laterally of said path and providing crank pins, and links pivotally connected at a common point and each extending therefrom to a pivotal connection with a different one of said pins, the plane of said crank shafts being so related to said path that neither of the links connected to a crank pin is in dead-center relation to the crank of its shaft when said reciprocating member is-in either of its extreme positions.

5. In combination with a reciprocating member providin a'wrist pin, and a rotatable shaft disposed in the plane of alignment with the path of movement of said member; parallel crank shafts providing crank pins and equally spaced at opposite sides of said path, said crank shafts definin a plane obliquely intersecting said path w ereby the angle of obliquity exceeds forty-five degrees; and links pivotally connectedat a common pivot for relative movement in a common plane parallel to said path and perpendicular to the axes of said crank shafts and each extending .from said pivot to a pivotal connection with a difierent'one'of said pins.

6. In combination with a reciprocating member providing a wrist pin and a rotatable shaft disposed in the plane of alignment with the path of movement of said member; parallel crank shafts operatively connected to said first shaft and providing crank pins and having their axes disposed out of said plane, said crank shaft axes' defining.a plane obliquely intersecting said first plane. and links pivotally connected at a common point for relative movement in a common plane parallel to said path and perpendicular to the axes of said crank shafts and each extendin from said pivot to a pivotal connection witfi a different one of said pins.

7. In combination with a reciprocating member providing a wrist pin having its axes movable laterally thereof to define a fixed plane including said axis, and a rotatable shaft disposed in said plane; parallel crank shafts operatively connected with said first shaft and providing crank pins and having their axes dis osed out of said plane at opposite sides 't ereof, said crank shaft axes defining a plane obliquel intersectin said first lane; links pivotally c0 ecte with the different said crank ins; an a link pivotally connected with t e opposite ends of said first links and with said wrist pin.

In testimony whereof, I afiix my s1 ature.

\ OLL HAMM ND. 

